1). "Now concerning
the coming of our Lord Jesus Christ and our being gathered together to Him"
2). "alleging that the
Day of the Lord has already come"
First, the second coming is when the Lord returns to the earth to end the age and establish His millennial kingdom. In opposition, the coming of our Lord and our being gathered to Him is referring to the resurrection of the dead in Christ and the living being changed and caught up with them to meet the Lord in the air. When Jesus appears to gather the church, He will not be returning to the earth, but will meet us in the air and take us back to the Father's house according to His promise in John 14:1-3.
The "Day of the Lord" mentioned in verse two, is referring to the time of God's wrath which takes place after the church has been gathered. Here is a better translation of that scripture:
"Now concerning
the coming of our Lord Jesus Christ and our being gathered together to Him, we ask you, brothers,
2not to be easily disconcerted or alarmed by any spirit or message or letter seeming to be from us, alleging that
the Day of the Lord has already come."
The coming of our Lord and our being gathered to Him, is a blessed event, the removal of the church prior to the beginning of God's wrath. In opposition, the Day of the Lord will not be a bless event, but represents the time of God's wrath.
Our being gathered to the Lord takes place first and is then followed by the Day of the Lord. Many do not recognize the change Paul makes regarding these two events. Though these events are closely link together, they are not the same.
The Thessalonians knew Paul's teachings, that the Lord would descend and with the trumpet of God the dead in Christ would rise first. And immediately following that, the living would be changed and caught up together with them. This is what Paul is speaking about in verse 1. The Thessalonians knew that after the gathering of the church had taken place that "The Day of the Lord" would immediately follow.
Since there were some there in Thessalonica teaching that "the Day of the Lord" had already come, the Thessalonians were concerned because they knew that if that were true, then they would have missed being gathered to the Lord and were now concerned about now being trapped in the Day of the Lord, the time of God's wrath. In other words they were saying, "Hey Paul, there are some here saying that the Day of the Lord has already come, so why are weren't we caught up to the Lord first according to your teachings? Then Paul comforts them by saying "not to be easily disconcerted or alarmed by any spirit or message or letter seeming to be from us, alleging that the Day of the Lord (the time of God's wrath) has already come." Paul didn't say, "not to be easily disconcerted or alarmed by any spirit or message or letter seeming to be from us, alleging that our being gathered to the Lord has already come." Do you see the difference? Paul starts off in Verse 1 with "the coming of our and our being gathered to Him" and then changes to "the Day of the Lord" calling it "that day." Then Paul says "Let no one deceive you in any way, for that day (Day of the Lord) will not come until the rebellion occurs and the man of lawlessness—the son of destruction—is revealed.
In order to understand what Paul is saying, t is important to discern the difference between the coming of Lord and our being gather vs. The Day of the Lord. It is also important to understand what "the Day of the Lord" is, which I've listed below:
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The great Day of the LORD is near—near and coming quickly.
Listen, the Day of the LORD!
Then the cry of the mighty will be bitter.
That day will be a day of wrath, a day of trouble and distress,
a day of destruction and desolation, a day of darkness and gloom,
a day of clouds and blackness, a day of horn blast and battle cry against the fortified cities, and against the high corner towers.
I will bring such distress on mankind that they will walk like the blind, because they have sinned against the LORD.
Their blood will be poured out like dust and their flesh like dung.
Neither their silver nor their gold will be able to deliver them on
the Day of the LORD’s wrath.
The whole earth will be consumed by the fire of His jealousy.”
For indeed, He will make a sudden end of all who dwell on the earth.
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The event of the coming of our Lord and our being gathered to Him is a different event and takes place prior to the Day of the Lord.
Our being gathered to the Lord is a blessing which takes place first. While the Day of the Lord will be the time of God's wrath, which follows our gathering.